The invention concerns a vehicle transmission according to the preamble of claim 1.
Modern, powerful vehicle transmissions mostly have a main transmission group with a multi-gear basic transmission and an integrated, front-mounted splitter group and a rear-mounted auxiliary group. They predominantly have a transmission housing with a first shaft, an input shaft and a second shaft, a central shaft or main shaft, which can also be the output shaft, and one or more countershafts. The input shaft and the main shaft are substantially concentric to each other. Such a transmission has been disclosed, for example, in DE 30 49 101 C2.
Taking into consideration the operating characteristics and the noise level, such transmissions can be designed with helical toothing at least for the forward gear range. The axial forces from the helical toothing must be absorbed by an axial support and be diverted toward the housing.
Transmissions of the described designs can be equipped with one countershaft or several countershafts.
In transmissions having power distribution to two countershafts, the main transmission group has two shafts substantially situated axially in tandem where the shaft is either the input shaft or the main shaft of the main transmission is radially and axially firmly supported while the respective other shaft is floatingly supported, that is, radially movable because of the needed balance. Note that an easy radial swiveling movement of the floating shaft is possible.
In transmissions having two countershafts, the load compensation can preferably be arranged so that the input shaft can be supported rigidly relative to the housing, the countershafts rigidly relative to the housing and the main shaft floatingly in the gears which are along the power flow.
In transmissions without power division, both shafts are supported radially and axially in the transmission housing, one shaft being supported on one side in a bearing within the other central shaft.
However, the existing supports have disadvantages that have to be overcome. Especially to be improved is the support of a helically toothed and radially movable shaft in a transmission housing for discharging axial forces toward the housing.